Attachment J - DVM FY18 FAC 10168 Tank 25 Final.pdf

QUALITY TESTING & INSPECTION

Lindon Utah/Phoenix Arizona

UT: 801-785-1111/AZ: 480-369-6511

INTERNAL AND EXTERNAL API 653 INSPECTION

FOR

DAVIS-MONTHAN AIR FORCE BASE

FLAT BOTTOM, JET FUEL, STORAGE TANK

WITH COVERED INTERNAL FLOATING ROOF

TANK 25: 100’-0” DIAMETER x 48’-0” HIGH

Inspection and report by Trent Pinckard NDT Technician, Tank & Pipe Specialist and Allan Oldham Calif Civil PE (# 41008), CWI (# 05090841), API 653 (# 60087)

Inspected on

7/16/2018 thru 7/19/2018

Constructed Second External Internal Shell UT

Bottom Inspection Inspection Inspection

1952 2010 10/26/2010 10/26/2010 10/26/2010

9/25/2014 9/25/2014 9/25/2014

7/16/2018 7/16/2018 7/16/2018

Next Inspection 2023 2038 2033

UT: 801-785-1111/AZ: 480-369-6511

Phone: 801-785-1111 Fax: 801-785-1120

100’ Ø X 48’ HIGH API 653 INSPECTION FOR DMAFB TANK 25 LOCATED AT TUCSON, ARIZONA

EXECUTIVE SUMMARY

Quality Testing and Inspection (QTI) was contracted by Weston Solutions to provide an Internal and External API 653 Inspection for Tank 25 at the Davis-Monthan AFB in Tucson, Az. Additionally, QTI was asked to review the extension of an existing gauge hatch thru the aluminum geodesic dome of the tank.

Some time between 2015 and 2017 the existing steel pontoon floating roof was replaced with an aluminum panel, full contact floating roof system. The tank was partially filled to ensure workability of the floating roof then taken out of service.

The original tank was built in 1952 by Chicago Bridge and Iron (CBI) in accordance with API 12C.

A new cone down 5/16-in double bottom installed in 2000.

The bottom incorporated an annular plate that was 0.337-in average thickness.

Field inspection and evaluations were performed in accordance with API 653.

Following the “Executive Summary” is a section of the report titled “API 653 Compliance”:

the subsection “Action Items” should be completed before the tank is returned to service.

The Action Items include only those elements necessary to bring the tank into service.

Those areas that do not meet the requirements of API 653 and API 650 but are not critical to bringing the tank into service, are noted.

According to API 653 6.3.1.1, routine inspections (in addition to formal API 653 inspections) using close visual inspection should be performed to determine the external condition of the tank on a periodic basis; not to exceed one month. If any leak paths or other adverse conditions are identified it should be documented and an authorized inspector notified.

All items shown in the “Executive Summary” has an associated Section in the body of the report.

For example, “Item 1” is a summary of a more detailed explanation in “Section 1”.

The thickness readings were taken with a GM DM5E UT Thickness Gauge ID #009148.

The transducer used during the inspection was 0.25 inch, 5 MHz, high damping.

Calibration was performed in accordance with ASME Section V, ASTM E114, ASTM E797 and Quality Testing and Inspection procedure QTI-UTTH-01 Rev 2.

The UT thickness gauge provides coating thicknesses and subtracts them from steel thickness.

Note: Table of Contents follows the “Executive Summary” and “API 653” sections of this report.

EXECUTIVE SUMMARY (CONTINUED)

Item 1: Geodesic Dome/Gauge Hatch Modification QTI was asked to determine the feasibility of extending a gauge hatch outside of the geodesic dome to eliminate the necessity of confined space entry for its access.

Extension of the gauge hatch interferes with the dome structure. To extend the gauge hatch beyond the geodesic dome, two braces must be moved vertically to intersect with the rafter.

Details are provided in Section 1 of this report.

A seal should be placed at the opening where the gauge pipe extends thru the roof.

Item 2: Identification of leak paths Evidence of serious corrosion which would cause leaks in the structural elements of the tank proper, were not found.

However, signs of leakage thru the floating roof were found.

The floating plate to plate joints will need to be resealed.

A ladder and three stilling wells protrude thru the floating roof.

The elastomeric seals for these protrusions have experience dry rot and will need to be replaced.

Details are provided in Section 2 of this report.

Evidence of moisture leaking thru the aluminum dome roof was also found.

Details are provided in Section 6 of this report.

Item 3: Shell and Bottom settlement A survey was performed on the tank bottom (including intersection with the shell) using a precision self-stabilizing laser level.

The shell and bottom settlements are compliant with API 653.

Details are provided in Section 3 of this report.

Item 4: Venting The floating roof is protected from under pressure by a single 36-in diameter pop-up style vent.

The vent appears to be working properly.

The tank proper is equipped with 6 shell overflow vents.

Item 5: Access Structure The access structures appear to be in good condition and OSHA compliant.

The 26-in width of the spiral stairway handrail is compliant with current OSHA regulations but can be grandfathered in.

Item 6: Aluminum Dome Roof The aluminum dome roof was inspected visually from the roof platforms.

Signs of corrosion severe enough to impact the structural integrity of the roof were not found.

However, from the vantage point of the roof platforms day light could be seen at some of the panel connections. Stains were visible at the interior of the dome suggesting moisture had seeped thru.

The moisture thru the geodesic dome is trapped on top of the floating roof.

Item 7: Floating Roof The tank is equipped with a single deck, full contact, sandwich panel, aluminum floating roof.

The floating roof is equipped with a double wiper seal.

The seal appears to be in good condition.

The floating roof is equipped with two anti-rotation cables.

Aside the from the issues noted in item 2 (leakage thru the panel joints and dry rot on some elastomeric seals) the floating roof appeared to be in good condition. This is expected as the floating roof has only been put into service once, for a short period of time.

Item 8: Tank Gauging Overfill Protection The tank gauging overfill protection was not operational at the time of inspection.

More details are provided in Section 8 of this report.

Item 9: Coatings and Chime Sealant Interior

283 DFT readings were taken on the tank bottom coatings.

There were 19 readings less than 5 mils thick (7% of the bottom DFT readings).

53 DFT readings were taken on the tank lower shell course readings.

There were 18 readings less than 5 mils thick (34% of the bottom DFT readings).

Item 9: Coatings and Chime Sealant (Continued) Interior (Continued)

There was general discoloration from water stains and isolated pockets of coating failure.

It is recommended that holiday (continuity) testing be performed on areas where the coating is damaged. Also, the tank interior coating should be monitored; isolated areas may be nearing the end of their useful life.

Exterior

Caulking at the interface of the bottom chime and the concrete pad needs repair to prevent moisture from infiltrating under the tank.

Item 10: Concrete Ring Wall and Concrete Dike The seal between the concrete under the tank and the surrounding pad has corroded thru and needs repair.

Cracks in the concrete have been caulked. But the cracks have grown beyond the caulking

The concrete facing on some of the support structures has begun to deteriorate.

Item 11: Weld Intersections Two locations were found on the bottom shell course, where the vertical shell joints aligned with the vertical shell joints of the upper course. This is in violation with API 650 (3.5-in minimum) and API 653 (10-in minimum).

Also, there are instances of bottom reinforcing pads not maintaining the required 2-in minimum distance from bottom lap welds.

This is covered in more detail in Section 11.

UT: 801-785-1111/AZ: 480-369-6511

API 653 COMPLIANCE

Action Items

1. To extend the gauge hatch beyond the geodesic dome, two stability braces must be relocated (see Section 1 of this report). A seal should be placed at the opening where the gauge pipe extends thru the roof.

2. The joints on the floating roof need to be re-sealed to prevent moisture from leaking thru.

3. The elastomeric seals on the floating roof for the stilling well and ladder need to be replaced.

4. At the time of inspection, no alarms or automatic liquid level gauges were operational.

These need to be made operational before putting the tank in service.

Consider Items

1. The interior coating needs to be carefully monitored.

The coating could fail prior to the next internal inspection.

Analysis of the “specific type of coating” applied and its current condition is recommended.

History is the best indicator. The coating performance of similar tanks and conditions is a good reference.

2. Caulking repair should be made to the interface of the bottom chime to the concrete pad.

3. The seal between the concrete under the tank and the surrounding pad needs to be repaired.

4. New cracks in the concrete pad should be repaired.

5. From the 2014 API 653 report, nozzle rotation was reported on the receiver to shell connection.

A nozzle rotation analysis can be performed to gain a better understanding of the interface stresses.

Monitor Items

1. The concrete facing on some of the support structures has begun to deteriorate.

2. A monthly walk around inspection of the tank should be made to make sure no leaking is occurring.

EXECUTIVE SUMMARY………………………………………2

API 653 COMPLIANCE………………………….……………6

GENERAL INFORMATION………………….……………….8

BASIC TANK INFORMATION …………………..………….9

SHELL SETTLEMENT SURVEY………………….………….10

NEXT INSPECTION……………………………….…………….12

SHELL ROLL-OUT DRAWING……………….……………..13

FLOATING ROOF DRAWING…………….…………………14

BOTTOM DRAWING…………………..……………………….15

SECTION 1 – GEODESIC DOME & HATCH MOD…...16

SECTION 2 - IDENTIFICATION OF LEAK PATHS……..29

SECTION 3 - BOTTOM SETTLEMENT……………………34

SECTION 4 – VENTING 37……………………………………37

SECTION 5 – ACCESS STRUCTURE……………………….38

SECTION 6 – ALUMINUM DOME ROOF……………….39

SECTION 7 – FLOATING ROOF……………………………..40

SECTION 8 – APPURTENANCES AND MANWAYS….43

SECTION 9 – COATINGS AND CHIME SEALANT…….73

SECTION 10 – CONCRETE RINGWALL…DIKE…………79

SECTION 11 – WELD INTERSECTIONS…………………..82

SECTION 12 – ULTRASONIC THICKNESS……………….87

APPENDIX A – API 653…CHECKLIST……………………..94

GENERAL INFORMATION

TANK DIAMETER 100’-0”

TANK HEIGHT 48’-0”

OPERATING

PRESSURE AMBIENT

OPERATING TEMP AMBIENT

CONTENTS JET A

SPECIFIC GRAVITY 0.84

NOMINAL CAPACITY 67,000 BBLS

MANUFACTURER CBI

DATE CONSTRUCTED 1952

MATERIAL

SHELL & BOTTOM

A283-C (EST)

STRUCTURAL DWGS NOT AVAILABLE

BOTTOM TYPE DOUBLE BOTTOM

ROOF TYPE ALUM GEODESIC

FLOATING ROOF

ALUM FULL

CONTACT

BASIC TANK INFORMATION

Tank Number: Tank Owner: Location: Unit/Area/Zone:

25 Davis Monthan AFB Tucson, AZ Fueling

Product: Diameter (ft.): Height: Capacity (bbls):

Jet Fuel 100' 48' 67,175

Type Tank: Year Built: Design Standard: Manufacturer:

aluminum floating roof 1952 API 12 C Chicago Bridge & Iron with Aluminum Dome

Type Shell: Type Roof: Type Foundation: Type Bottom:

Butt-Welded Aluminum Dome Concrete Ring sloping

Type Floating Roof: Type Primary Seal: Type Secondary Seal: Roof Drain:

Aluminum sandwich panel elastomer wiper elastomer wiper 3-In. Emergency Drain full contact

Roof Access: Floating Roof Access: Floating Roof Vents: Roof Manways:

Spiral Stairway Ladder 1: 36" pop up Access Hatch

Pumping Rate: Suction Line: Receipt: Shell Manways:

Unknown 1:16-In D, 33.33 ft. long 1:12-IN 3-36in. MW

Leak Detection:

Secondary Containment: Cathodic Protection: Insulation:

Tell Tales In Space Under Concrete Dike Sacrificial Anode None

2nd Bottom

UT: 801-785-1111/AZ: 480-369-6511

Phone: 801-785-1111 Fax: 801-785-1120

SHELL SETTLEMENT SURVEY

Blue is the predicted cosine curve.

Red is the actual measured values.

The variation in the shell elevations at the base of the footing are small, within the range of expected tolerances (1/2-in variation max). The elevations do not match a cosine curve.

Check foundation for allowable settlement per API 653 Figure B.4 and B.3.2.2.

Smax = K x Sarc x (D/H) x (Y/E) Smax = Permissible out of plane settlement, in inches Sarc = effective settlement arc per API 653 B.2.2.5.1 = distance of arc in question.

Point 8 to Point 10 governs: (30°/360°)(π)(100’) = 26.2’ K = value from table API 653 B.3.2.2 = 3.9 D = tank diameter in feet = 100.00 H = tank height in feet = 48 Y = shell material yield strength = 30,000 psi for A283-C material E = Modulus of elasticity = 29,000,000 ksi Smax = 3.9 x 26.2 x (100/48) x (30,000/29,000,000) = 0.22 inches The deflections obtained from this survey are similar to those obtained in 2010.

The methodology used for allowable shell settlement in API 653 contains approximations.

For example, a geodesic dome roof may not have as much stiffness as a traditional fixed roof.

If the tank was considered to be open top, with increased flexibility; Smax = 0.37 inches.

A more rigorous analysis (i.e. finite element) would be required before stating the tank had settlement issues.

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1 2 3 4 5 6 7 8 9 10 11 12 13

Shell Settlement

SHELL THICKNESS CALCULATION

Shell thickness calculations per API 653 4.3.3.1 to find t min.

Determine liquid level (H) to over flow openings.

Overall shell height is 48.00’.

Distance from first tank bottom to second tank bottom: 1.67 feet.

Distance from first tank top to over flow: 4.75 feet.

H = 48 – 1.67 – 4.75 = 41.58’. Previous inspection used 42’ => use the same for this inspection.

Variables D = tank diameter: 100’ G = specific Gravity; 0.84 E = joint efficiency; 0.85

S = allowable stress (API 653 Table 4-1); 23,600 psi lower two courses & 26,000 psi remainder t actual = lowest recorded value for the shell course under consideration.

t min = 2.6(H-1)DG/(SE)

Course 1 H = 42.00’ t min = 0.446” t actual = 0.684” ok Course 2 H = 34.00’ t min = 0.359” t actual = 0.564” ok Course 3 H = 26.00’ t min = 0.247” t actual = 0.467” ok

Course 4 H = 18.00’ t min = 0.168” t actual = 0.347” ok Course 5 H = 10.00’ t min = 0.100” t actual = 0.250” ok Course 6 H = 2.00’ t min = 0.100” t actual = 0.250” ok

Shell Corrosion Rate Calculations per API 653

Inspection of the shell thickness measurements from 2010 to 2018 indicate corrosion is negligible. Therefore, the corrosion rate for this period is negligible.

The shell thickness shown for course 1 comes from a single make-up plate which was thinner than all other course 1 plates.

The remaining course 1 plates indicate there has been no corrosion since 2010.

Shell Shell

Thickness

Course 2010 2014 2018

1 0.697 0.697 0.684

2 0.565 0.700 0.564

3 0.467 0.554 0.467

4 0.340 0.430 0.347

5 0.240 0.250 0.250

6 0.250 0.225 0.250

NEXT INSPECTION

Shown in the previous section, the shell corrosion is negligible.

Determine the effects of bottom corrosion.

Year Bottom Thickness Annular PL Thickness 2010 0.300 to 0.320 not available 2014 0.289 to 0.311 not available 2018 0.316 (Note 1) 0.330 to 0.358

Note 1: thickness is the average of 411 readings.

The bottom corrosion is negligible.

For the sake of report completeness, “MRT” (Minimum Remaining Thickness) methodology will be considered for the bottom.

MRT = (Minimum of RTbc or RTip) – Or(StPr – UPr)

MRT = minimum remaining thickness at the end of interval Or .

Or = in service interval of operation (20 years).

RTbc = remaining thickness of bottom side corrosion after repairs (0.316”).

RTip = remaining thickness of internal corrosion after repairs (0.316”).

StPr = 0 for coated areas of the bottom.

For this to be valid periodic checks must be made to ensure the bottom coating has remained intact.

UPr = maximum rate of corrosion on the bottom side (0”).

UPr is 0 when an effective cathodic protection system is in place.

Such a system is in place but readings were not available for review.

MRT = 0.316” – 20 (0 – 0) => Interval of 20 years acceptable providing interior lining is maintained.

SHELL ROLL-OUT DRAWING

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S H

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T

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M A

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M A

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2'-8" HIGH DOUBLE BOTTOM

ALUMINUM DOME ROOF

H I-

A L A

R M

P

L A

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SHELL FLOATING ROOF DRAWING

33 FLOATING ROOF

SUPPORT LEGS

FLOATING ROOF SEAL

36" VENT

30" MANWAY

6" STILLING WELL

8" STILLING WELL

LADDER

BOTTOM DRAWING

480 SQ. INCHES

12" RECEIPT

3" LINE

1" LINE

16" SUCTION LINE

24" DI x 1/2 IN

PIPE CAP SUMP

5/16" NOMINAL

BOTTOM PLATES

.34" AVERAGE

ANNULAR RING

6" STILLING WELL

8" STILLING WELL

NORTH

LADDER

1 2 3

4 5 6 7

8 9

10 11

14 15 16 17

18 19 20 21 22

24 25 26 27 28

3332313029

34 35 37 38 39

40 41 42 43 44

46 47 48 49 50

53 54 55

56 57 58 59 60 61

62 63 64 65 66

67 68 69 70 71

72 73 74 75 76

77 78 79 80

81 82 83

36" MANWAY

36" MANWAY

36" MANWAY

DIFFUSER 10" DIA

SECTION 1: GEODESIC DOME/GAUGE HATCH MODIFICATION

The gauge well terminated below the geodesic aluminum dome roof.

This required a confined space entry every time the gauge well was used.

An investigation was made to determine the feasibility of extending the gauge well above the roof.

SECTION 1: GEODESIC DOME/GAUGE HATCH MODIFICATION (CONTINUED)

The gauge well was located near the geodesic dome roof hatch.

There are L 3 x 2 x 3/16 braces that connect from the bottom dome ring to the rafter.

This only occurs on the bottom chords.

The gage well is directly below the L 3 x 2 x 3/16 brace and very close to an existing electrical conduit.

Nearby there is also a brace for the electrical line that also interferes.

Unbolting and removing the electrical line brace will facilitate extending the gauge well.

The opposite end of the electrical line brace is shown at left.

The sketch below shows a simple framing plan of the area of interest.

The brace that interferes with the gauge hatch consists of 2 ~ L 3 x 2 x 3/16.

All other braces performing a similar function are 1 1/2 x 1 1/2 x 1/8.

This means the brace over the gauge hatch has more than double the structural properties of the other braces. The roof hatch appears to be a modification of an earlier structural system. The intent is to maintain the current structural system.

Note: the brace interferes with the corner of the roof hatch.

The picture below shows the interference between the bottom chord brace and the roof hatch.

The existing brace to rafter connection is shown below.

Note: the brace attaches to the weak axis of the C section rafter. The C section rafter must resist vertical DL + LL and wind loads in the strong axis.

This means the anticipated load from the brace must be small. Such situations occur when reducing the unbraced length in main members.

A plan view of the extended gauge well area is shown below.

Remove the existing electrical line brace. The bottom angle of the line brace can remain.

The existing lower chord brace should be modified in a way that is least invasive and results in the least amount of rework.

The picture below shows the connection of the lower chord with the brace.

The brace consists of two L 3 x 2 x 3/16 angles (long leg horizontal).

They are attached to a C4 aluminum structural chord.

As will be shown later in the report, this connection can remain intact.

The picture below shows the connection of the brace with the geodesic dome rafter.

The two L 3 x 2 x 3/16 angles (long leg horizontal) are fastened with one bolt.

They are attached to a C4 aluminum rafter.

As will be shown later in the report, this connection will need to be moved.

The roof hatch is supported by bolted L 3 x 3 x 1/4 angles. It is intended to leave these fasteners undisturbed.

The modified brace is shown below.

Trim to fit the upper modified brace.

This angle of connection introduces a smaller force on the weak axis of the dome rafter.

The edge of the modified brace will protrude approximately 2” beyond the edge of the roof hatch. Bring the edge of the brace even to the heads of the fasters and existing angles.

After aligning the two brace pieces, use a full pen weld on each leg of both angles.

A PL 4” x 6” x 1/4" should be welded on the upper face of the top and bottom braces.

This is to add additional strength at the point of eccentricity.

It will be easier to weld the plate on the bottom brace if it is done prior to aligning and welding the upper brace.

For the plate and angle brace use 6061 aluminum.

NOTE: THE BEND IN THE BRACE IS ONLY TO LEAVE THE ROOF HATCH AS OPEN AS POSSIBLE.

THE 2 ~ L 3 X 2 X 3/16 ANGLES CAN BE LEFT STRAIGHT. BUT WITH AN ADDITIONAL ENCROACHMENT

OF 2” AT 12” UP, TAPERING TO THE SAME AT THE TOP.

SECTION 2: IDENTIFICATION OF LEAK PATHS

Rain had occurred just prior to the API 653 inspection. Pooling was found on the bottom.

Moisture could be found dripping at several locations from the bottom of the floating roof.

Example locations of moisture on the floor are shown below.

Some locations were known to be due to leakage from the floating roof, as dripping could be seen coming thru. Other locations bore a strong resemblance to known dripping. These are noted as possible roof leaks.

SECTION 2: IDENTIFICATION OF LEAK PATHS (CONTINUED)

Pictures of the rain pooling on the floating roof are shown below.

Pooling on the top surface of the floating roof was seeping thru the caulked joints on the bottom surface.

There are several possible areas that could be sources for leakage on the floating roof.

In the above pictures of water pooling on the floating, the reflection of roof vents and overflow vents are visible. Pictures of the roof vent surrounding the tank are shown below.

UT: 801-785-1111/AZ: 480-369-6511

The vent is covered from the top. But this does not completely stop rain when large wind gusts are present.

A similar condition exists with the overflows and center roof vent.

As stated previously a gap exists in sealant between some of the roof panels.

Leak paths exist for moisture to accumulate on the floating roof; where pools of water become trapped.

Dry rot has occurred in the stilling well and ladder elastomeric seals. These seals will need to be replaced.

SECTION 3: BOTTOM SETTLEMENT

TANK SURVEY LAYOUT

0° Located at CL Receiver

0°

330°

300°240°

210°

180°

150°

120°

90°

60°

30°

20' 30' 40' 50'

SECTION 3: BOTTOM SETTLEMENT (CONTINUED)

TANK SURVEY LAYOUT

10' 20' 30' 40' 50'

0º 3" 6-1/4" 1' 1/2" 1' 4-1/2" 1' 9-1/4"

30º 3" 9-1/2" 1' 2" 1' 5-1/2" 1' 9"

60º 2-1/2" 6-1/2" 11-1/4" 1' 4-3/4" 1' 9-1/4"

90º 2" 7" 1' 1-1/2" 1' 5-1/2" 1' 9-1/4"

120º 2" 9" 1' 3/4" 1' 5-1/2" 1' 9-1/4"

150º 1-3/4" 8-1/2" 1' 3" 1' 6-3/4" 1' 8-3/4"

180º 2" 7-1/2" 1' 1" 1' 5" 1' 9"

210º 0" 4-1/2" 11-1/4" 1' 2-1/2" 1' 8-3/4"

240º 0" 3-1/2" 10-1/4" 1' 3-1/2" 1' 9"

270º 1-1/4" 3" 11-1/4" 1' 4-3/4" 1' 9"

300º 2-1/2" 7-3/4" 11-1/4" 1' 3" 1' 9-1/4"

330º 3-1/4" 8-1/4" 11-1/4" 1' 5-1/2" 1' 9"

API 653 B.3.3 provides the following formula to assess tank bottom settlement.

BB = 0.37 R BB = Maximum allowable depression (inches) R = Radius of inscribed depression (feet)

When laying a straight edge along the bottom to account for slope and using mathematical evaluations of the survey, the tank bottom was found to be within the limits of the table shown at left. Note: walking on the tank floor was enough to make measurable changes in elevation.

R (ft) BB (in)

2.5 0.93

5 1.85

10 3.70

15 5.55

SECTION 3: BOTTOM SETTLEMENT (CONTINUED)

Layouts of the survey are shown below. The bottom follows the desired slope, except there is a flat spot near the center of the tank at grids 210° to 270°.

SECTION 4: VENTING

The floating roof is protected from under pressure by a single 36-in diameter pop-up style vent.

Venting is provided along the perimeter of the tank.

The mesh is protected by a cover 8” wide with a 3” lip.

The tank is also equipped with 6 shell overflow vents.

SECTION 5: ACCESS STRUCTURE

The access structures appear to be in good condition and generally OSHA compliant.

Stairway Requirements

Handrail Stair Stair

Height Rise Width OSHA 30” 6” to 7.5” 28” ACTUAL 32” min 6” to 7.5” 26.75”

The 26-in width of the spiral stairway handrail is not compliant with current OSHA regulations but can be grandfathered in.

SECTION 6: ALUMINUM DOME ROOF

The geodesic dome is a 7 segment, 4 frequency, 112 panel design.

Panel thickness measurements were taken on panels that were accessible from platforms.

The thicknesses were relatively uniform; ranging from 0.042 to 0.044 inches thick.

Note: the panels and chords change dimensions as they form the roof.

Any alteration or replacement will require measuring each panel and structural member independently.

More details of the geodesic dome can be found in Section 1 of this report.

SECTION 7: FLOATING ROOF

The floating roof primary and secondary seals were in good condition.

Other details of the floating roof are scattered throughout the report.

SECTION 7: FLOATING ROOF CONTINUED

SECTION 7: FLOATING ROOF CONTINUED

SECTION 8: APPURTENANCES AND MAN WAYS

There are three stilling wells. All were in excellent condition.

SECTION 8: APPURTENANCES AND MAN WAYS CONTINUED

Two stilling wells were 8” diameter x 0.33” thick.

One stilling well was 6” diameter x 0.28” thick, All slots were 1-1/2” x 9-1/2”, The interior suction lines are shown below.

There are three 36” diameter manways.

Some corrosion has occurred at the hanger to manway lid connection, but not sufficient to impair its ability to function as intended. The man ways were found to meet the requirements of API 650 and

API 653.

The tank is equipped with 8 sample ports and 4 grounding lugs.

Sample ports and grounding lugs continued.

Exterior suction line is shown below.

Exterior suction line continued.

UT: 801-785-1111/AZ: 480-369-6511

Exterior receiving line is shown below.

Exterior receiving line continued.

Upper sensor assembly is shown below.

Upper sensor assembly continued.

UT: 801-785-1111/AZ: 480-369-6511

Lower sensor assembly shown below.

Lower sensor assembly continued.

When compared with the height of floating roof, the liquid level gauge appeared to be reading correctly.

Other appurtenances.

Other appurtenances.

SECTION 9: COATINGS AND CHIME SEALANT

Dry film thickness readings for the coating of the bottom plates are shown below.

Three random readings were taken on each plate. Those areas that were visually thin were tested.

Areas less than 4 mils are shown in red.

Plate A (mils) B (mils) C (mils) Plate A (mils) B (mils) C (mils)

1 11.5 3.0 3.0 26 14.5 14.5 21.0

2 3.5 12.0 10.0 27 6.5 9.5 11.0

3 19.0 20.0 10.5 28 7.5 8.5 9.5

4 16.5 10.0 9.0 29 9.0 5.0 7.0

5 9.5 12.0 7.0 30 8.0 7.0 5.5

6 5.5 5.5 10.5 31 12.0 9.5 8.5

7 4.0 3.0 10.0 32 16.5 7.0 10.0

8 8.0 1.5 11.0 33 12.0 11.5 7.0

9 8.5 9.5 5.5 34 12.0 8.5 5.5

10 9.0 16.5 16.0 35 12.5 5.5 4.5

11 10.5 7.0 10.0 36 4.5 9.0 9.0

12 4.0 16.0 8.0 37 10.5 6.0 4.0

13 4.0 8.5 10.5 38 5.5 11.0 11.5

14 8.0 9.0 6.0 39 9.0 10.5 8.0

15 12.0 13.0 10.5 40 9.0 9.5 4.0

16 7.0 7.5 6.0 41 4.5 5.5 6.5

17 11.0 9.5 9.5 42 9.0 8.0 7.5

18 11.0 7.5 13.0 43 8.5 12.0 12.5

19 8.0 5.5 13.5 44 7.0 8.0 9.0

20 8.0 9.0 8.5 45 9.0 5.0 4.5

21 7.0 9.5 7.0 46 7.5 3.0 6.5

22 7.5 9.0 12.0 47 4.5 7.5 7.0

23 11.0 12.5 11.0 48 6.5 8.0 5.5

24 4.5 7.0 5.5 49 4.5 8.0 9.0

25 11.5 8.5 8.5 50 7.5 6.5 10.0

SECTION 9: COATINGS AND CHIME SEALANT (CONTINUED)

Dry film thickness readings for the coating of the bottom plates are continued below.

Areas less than 4 mils are shown in red.

51 6.0 4.5 3.0 76 11.0 8.0 8.5

52 5.0 4.0 3.0 77 11.5 6.5 14.0

53 6.5 4.5 3.5 78 9.5 8.0 9.0

54 4.0 7.5 4.5 79 10.5 12.0 7.5

55 4.0 7.0 6.5 80 13.5 8.5 6.0

56 7.0 4.5 9.5 81 10.0 12.0 11.5

57 2.5 4.5 6.0 82 11.0 11.5 9.0

58 8.0 10.0 10.5 83 7.5 9.5 7.0

59 6.0 12.0 13.0

60 11.5 4.0 9.5

61 5.0 5.0 3.0

62 5.0 3.5 3.0

63 5.0 5.0 5.5

64 3.5 15.0 10.5

65 8.5 7.0 14.0

66 6.5 14.5 7.5

67 9.0 3.5 5.0

68 5.0 9.0 6.0

69 7.0 7.0 6.5

70 5.5 9.5 11.0

71 9.5 5.5 10.5

72 10.5 11.5 12.0

73 10.0 9.0 13.5

74 14.5 13.5 12.0

75 11.5 14.0 9.0

Dry film thickness readings for the coating of the annular plates are shown below.

There are isolated pockets of paint failure (see pictures at right).

It is recommended that holiday (continuity) testing be performed on areas where the coating is damaged. Also, the tank interior coating should be monitored; isolated areas may be nearing the end of their useful coating life.

Plate A B

84 11.5 13.5

85 14.0 12.0

86 14.0 10.0

87 16.0 10.5

88 9.0 9.5

89 8.0 13.0

90 11.0 9.5

91 11.0 5.5

92 9.5 10.5

93 15.5 11.5

94 11.5 14.0

95 8.5 8.0

96 6.5 8.0

97 14.0 9.5

98 9.0 15.5

99 14.5 8.5

100 11.5 8.5

Dry film thickness readings for the internal shell.

DFT Readings DFT Readings

6 ft on center. 6 ft on center.

3 ft from bottom. 3 ft from bottom.

1 10.0 27 4.5

2 4.0 28 8.5

3 9.0 29 7.5

4 4.0 30 7.5

5 2.5 31 6.5

6 3.0 32 11.0

7 4.5 33 10.5

8 4.5 34 4.5

9 3.0 35 11.0

10 3.0 36 11.5

11 9.0 37 5.0

12 4.5 38 3.5

13 2.5 39 5.0

14 4.0 40 9.0

15 5.0 41 8.0

16 5.5 42 8.0

17 4.5 43 5.5

18 6.0 44 10.5

19 6.0 45 6.5

20 6.5 46 5.0

21 10.0 47 9.0

22 12.5 48 6.5

23 6.5 49 5.5

24 9.5 50 4.0

25 10.0 51 4.5

26 10.0 52 8.5

Dry film thickness readings taken from the external tank shell are shown below.

DFT Readings taken

DFT Readings taken

20" on center up 20" on center up length of stairway length of stairway

1 13.0 15 7.5

2 6.0 16 16.5

3 15.0 17 12.0

4 15.5 18 13.0

5 6.0 19 14.5

6 8.5 20 10.0

7 11.5 21 12.0

8 11.0 22 13.0

9 10.5 23 11.5

10 9.5 24 13.5

11 7.0 25 7.5

12 13.0 26 11.5

13 6.0 27 12.0

14 10.0 28 11.0

Pictures of the chime sealant that needs repair are shown below.

Note also those areas of the chime where paint is worn.

SECTION 10: CONCRETE RINGWALL AND CONCRETE DIKE

Failure of the sealant between the tank pad and surrounding pad are shown below.

Picture of crack extend beyond repair shown below.

Pictures of the concrete facing peeling off are shown below.

Other pictures of the concrete pad and dike follow.

SECTION 11: WELD INTERSECTIONS

Per API 650, 5.1.5.2 (b); “Vertical joints in adjacent shell courses shall be…offset from each other a minimum distance of 5t, where t is the plate thickness of the thicker course…” Using a shell thickness of 0.7”, the minimum offset distance would be 3.5 inches.

API 653 Figure 9.1 stipulates 10” for a shell offset for door plate cutouts.

Two locations were found on the bottom shell course, where it aligned with the upper course.

If there are no records of radiography performed at these locations, phased array ultrasonic should be considered as a means of ensuring the structural integrity of the joints.

SECTION 11: WELD INTERSECTIONS (CONTINUED)

It is good practice to make an extra careful visual check of the welds at intersections where the annular plate butt joints are close to the bottom lap welded joints. No relevant indications were found.

API 653, Figure 9.13 stipulates a 2-inch minimum distance from a bottom lap plate seam to a bottom reinforcing pad. The are reinforcing plates on the tank that violate this stipulation. A careful visual inspection was performed in these areas. No relevant indications were found.

Below are more examples that violates the 2-inch minimum distance from a bottom lap plate seam to a bottom reinforcing pad.

API 653, Figure 9.13 also stipulates a 2-inch minimum distance when a bottom lap plate seam is crossed by a bottom reinforcing pad. There are reinforcing plates on the tank that violate this stipulation. A careful visual inspection was performed in these areas. No relevant indications were found.

It should be noted that most of the bottom reinforcing plates had no distance violation.

Examples are shown below.

SECTION 12: ULTRASONIC THICKNESS READINGS

Ultrasonic Thickness Reading for the Bottom Rectangular plates have 5 readings. Triangular plates have four readings.

Plate A B C D E

1 0.316 0.302 0.299 0.321

2 0.299 0.338 0.323 0.344 0.348

3 0.359 0.335 0.338 0.330

4 0.337 0.349 0.333 0.361 0.331

5 0.355 0.342 0.332 0.332 0.334

6 0.301 0.333 0.318 0.336 0.303

7 0.294 0.328 0.298 0.295 0.296

8 0.341 0.292 0.298 0.319 0.329

9 0.335 0.295 0.341 0.320 0.297

10 0.350 0.339 0.350 0.294 0.297

11 0.328 0.336 0.333 0.305 0.335

12 0.334 0.333 0.305 0.335 0.303

13 0.318 0.289 0.289 0.290 0.306

14 0.343 0.328 0.291 0.331 0.294

15 0.314 0.321 0.322 0.318 0.349

16 0.368 0.344 0.301 0.299 0.298

17 0.331 0.305 0.320 0.330 0.328

18 0.303 0.304 0.336 0.303 0.306

19 0.322 0.289 0.316 0.347 0.300

20 0.327 0.287 0.315 0.325 0.315

21 0.319 0.291 0.345 0.290 0.355

22 0.331 0.306 0.343 0.306 0.304

23 0.305 0.304 0.325 0.305 0.305

24 0.299 0.333 0.318 0.298 0.329

25 0.330 0.299 0.339 0.334 0.328

26 0.351 0.330 0.319 0.330 0.299

27 0.305 0.350 0.307 0.335 0.352

28 0.297 0.332 0.301 0.296 0.318

29 0.328 0.321 0.300 0.299 0.299

30 0.298 0.299 0.301 0.299 0.328

Plate A B C D E

31 0.338 0.303 0.336 0.302 0.325

32 0.301 0.303 0.319 0.329 0.303

33 0.324 0.307 0.305 0.312 0.325

34 0.301 0.301 0.317 0.298 0.319

35 0.301 0.296 0.319 0.333 0.303

36 0.303 0.312 0.301 0.327 0.299

37 0.302 0.299 0.319 0.333 0.340

38 0.300 0.312 0.315 0.301 0.313

39 0.316 0.310 0.301 0.311 0.301

40 0.330 0.299 0.302 0.327 0.317

41 0.330 0.317 0.300 0.323 0.313

42 0.315 0.324 0.315 0.322 0.315

43 0.318 0.297 0.299 0.326 0.302

44 0.317 0.330 0.305 0.302 0.300

45 0.300 0.310 0.326 0.300 0.301

46 0.310 0.305 0.301 0.330 0.302

47 0.300 0.312 0.315 0.316 0.301

48 0.318 0.300 0.301 0.303 0.314

49 0.300 0.300 0.330 0.329 0.300

50 0.330 0.302 0.305 0.330 0.322

51 0.304 0.300 0.321 0.330 0.307

52 0.330 0.315 0.309 0.305 0.301

53 0.304 0.300 0.315 0.300 0.304

54 0.301 0.326 0.301 0.301 0.300

55 0.302 0.328 0.300 0.302 0.323

56 0.300 0.302 0.303 0.318 0.321

57 0.321 0.316 0.330 0.333 0.332

58 0.335 0.318 0.317 0.326 0.302

59 0.320 0.299 0.300 0.303 0.303

60 0.322 0.300 0.311 0.336 0.298

Plate A B C D E

61 0.329 0.312 0.331 0.330 0.332

62 0.332 0.329 0.301 0.302 0.326

63 0.335 0.325 0.316 0.304 0.307

64 0.300 0.308 0.332 0.301 0.319

65 0.311 0.312 0.304 0.316 0.302

66 0.300 0.324 0.315 0.300 0.329

67 0.330 0.312 0.333 0.324 0.330

68 0.300 0.301 0.300 0.323 0.326

69 0.302 0.300 0.317 0.300 0.300

70 0.307 0.305 0.304 0.298 0.338

71 0.329 0.323 0.334 0.318 0.360

72 0.304 0.303 0.321 0.324 0.303

73 0.365 0.334 0.335 0.307 0.327

74 0.313 0.316 0.330 0.317 0.322

75 0.316 0.322 0.321 0.300 0.300

76 0.302 0.335 0.303 0.300 0.325

77 0.319 0.300 0.300 0.314 0.300

78 0.300 0.295 0.297 0.325 0.338

79 0.294 0.295 0.298 0.301 0.327

80 0.330 0.321 0.301 0.311 0.300

81 0.303 0.301 0.324 0.320

82 0.332 0.320 0.312 0.321 0.308

83 0.321 0.319 0.321 0.314

D

A

B

C

D

E A

B C

Ultrasonic Thickness Reading for the Bottom Critical Zone (Annular Plate)

Reading Ft. In. UT (in.) Reading Ft. In. UT (in.)

1 314 3768 0.358 31 254 3048 0.340

2 312 3744 0.335 32 252 3024 0.349

3 310 3720 0.337 33 250 3000 0.341

4 308 3696 0.354 34 248 2976 0.333

5 306 3672 0.336 35 246 2952 0.333

6 304 3648 0.337 36 244 2928 0.335

7 302 3624 0.335 37 242 2904 0.341

8 300 3600 0.340 38 240 2880 0.331

9 298 3576 0.336 39 238 2856 0.339

10 296 3552 0.350 40 236 2832 0.340

11 294 3528 0.344 41 234 2808 0.330

12 292 3504 0.350 42 232 2784 0.340

13 290 3480 0.334 43 230 2760 0.340

14 288 3456 0.333 44 228 2736 0.345

15 286 3432 0.334 45 226 2712 0.332

16 284 3408 0.331 46 224 2688 0.330

17 282 3384 0.333 47 222 2664 0.340

18 280 3360 0.336 48 220 2640 0.340

19 278 3336 0.330 49 218 2616 0.345

20 276 3312 0.334 50 216 2592 0.331

21 274 3288 0.330 51 214 2568 0.330

22 272 3264 0.332 52 212 2544 0.337

23 270 3240 0.337 53 210 2520 0.333

24 268 3216 0.332 54 208 2496 0.339

25 266 3192 0.333 55 206 2472 0.334

26 264 3168 0.332 56 204 2448 0.340

27 262 3144 0.336 57 202 2424 0.332

28 260 3120 0.339 58 200 2400 0.340

29 258 3096 0.340 59 198 2376 0.337

30 256 3072 0.340 60 196 2352 0.339

Reading Ft. In. UT (in.) Reading Ft. In. UT (in.)

61 194 2328 0.340 91 134 1608 0.348

62 192 2304 0.340 92 132 1584 0.340

63 190 2280 0.341 93 130 1560 0.332

64 188 2256 0.337 94 128 1536 0.334

65 186 2232 0.330 95 126 1512 0.330

66 184 2208 0.339 96 124 1488 0.340

67 182 2184 0.339 97 122 1464 0.350

68 180 2160 0.330 98 120 1440 0.332

69 178 2136 0.331 99 118 1416 0.333

70 176 2112 0.336 100 116 1392 0.338

71 174 2088 0.336 101 114 1368 0.338

72 172 2064 0.340 102 112 1344 0.339

73 170 2040 0.349 103 110 1320 0.340

74 168 2016 0.358 104 108 1296 0.342

75 166 1992 0.347 105 106 1272 0.330

76 164 1968 0.348 106 104 1248 0.330

77 162 1944 0.332 107 102 1224 0.341

78 160 1920 0.348 108 100 1200 0.330

79 158 1896 0.347 109 98 1176 0.338

80 156 1872 0.345 110 96 1152 0.338

81 154 1848 0.330 111 94 1128 0.339

82 152 1824 0.330 112 92 1104 0.340

83 150 1800 0.331 113 90 1080 0.342

84 148 1776 0.334 114 88 1056 0.331

85 146 1752 0.332 115 86 1032 0.330

86 144 1728 0.330 116 84 1008 0.341

87 142 1704 0.331 117 82 984 0.330

88 140 1680 0.340 118 80 960 0.331

89 138 1656 0.336 119 78 936 0.339

90 136 1632 0.340 120 76 912 0.331

UT: 801-785-1111/AZ: 480-369-6511

Reading Ft. In. UT (in.) Reading Ft. In. UT (in.)

91 134 1608 0.348 125 66 792 0.330

92 132 1584 0.340 126 64 768 0.343

93 130 1560 0.332 127 62 744 0.346

94 128 1536 0.334 128 60 720 0.336

95 126 1512 0.330 129 58 696 0.338

96 124 1488 0.340 130 56 672 0.338

97 122 1464 0.350 131 54 648 0.337

98 120 1440 0.332 132 52 624 0.336

99 118 1416 0.333 133 50 600 0.339

100 116 1392 0.338 134 48 576 0.339

101 114 1368 0.338 135 46 552 0.330

102 112 1344 0.339 136 44 528 0.339

103 110 1320 0.340 137 42 504 0.330

104 108 1296 0.342 138 40 480 0.340

105 106 1272 0.330 139 38 456 0.331

106 104 1248 0.330 140 36 432 0.340

107 102 1224 0.341 141 34 408 0.334

108 100 1200 0.330 142 32 384 0.334

109 98 1176 0.338 143 30 360 0.332

110 96 1152 0.338 144 28 336 0.333

111 94 1128 0.339 145 26 312 0.340

112 92 1104 0.340 146 24 288 0.342

113 90 1080 0.342 147 22 264 0.340

114 88 1056 0.331 148 20 240 0.346

115 86 1032 0.330 149 18 216 0.330

116 84 1008 0.341 150 16 192 0.340

117 82 984 0.330 147 22 264 0.340

118 80 960 0.331 148 20 240 0.346

119 78 936 0.339 149 18 216 0.330

120 76 912 0.331 150 16 192 0.340

121 74 888 0.339 151 14 168 0.338

122 72 864 0.349 152 12 144 0.340

123 70 840 0.333 153 10 120 0.337

124 68 816 0.340 154 8 96 0.333

155 6 72 0.340

156 4 48 0.332

157 2 24 0.330

Ultrasonic Thickness Reading for the Shell Course 1

Course 1 A B C D E

Plate 1 0.729 0.728 0.730 0.732 0.720

Plate 2 1.013 1.052 1.016 1.039 1.018

Plate 3 0.687 0.688 0.686 0.689 0.684

Plate 4 0.705 0.715 0.713 0.715 0.705

Plate 5 0.711 0.706 0.709 0.717 0.720

Plate 6 0.707 0.715 0.718 0.721 0.723

Plate 7 0.715 0.716 0.718 0.711 0.720

Plate 8 0.723 0.706 0.714 0.712 0.719

Plate 9 0.708 0.717 0.708 0.732 0.723

Plate 10 0.712 0.713 0.716 0.714 0.707

Plate 11 0.709 0.713 0.713 0.721 0.719

Plate 12 1.050 1.044 1.045 1.034 1.051

Plate 13 0.703 0.704 0.719 0.710 0.708

Plate 14 0.706 0.701 0.717 0.715 0.722

Plate 15 0.720 0.714 0.713 0.717 0.717

Plate 16 0.718 0.720 0.718 0.720 0.722

Plate 17 0.722 0.716 0.719 0.719 0.716

Plate 18 0.707 0.718 0.717 0.716 0.716

Plate 19 0.712 0.714 0.716 0.716 0.709

Ultrasonic Thickness Reading for Shell Courses 2 thru 6

Course 2 A B C D E

Plate 1 0.567 0.568 0.567 0.564 0.565

Course 3 A B C D E

Plate 1 0.467 0.470 0.470 0.471 0.470

Course 4 A B C D E

Plate 1 0.350 0.347 0.347 0.354 0.347

Course 5 A B C D E

Plate 1 0.250 0.250 0.251 0.250 0.251

Course 6 A B C D E

Plate 1 0.250 0.251 0.250 0.251 0.252

Type Ø Top Left Bot Right Repad Orig Thk

Min.

Thk Year Inst Cor Rate Next Insp

A - Receipt 12" 0.500 0.500 0.495 0.500 1.000 N/A 0.495 1952 0.00 15+ Years

B - MW 36" 0.500 0.500 0.497 0.499 1.000 N/A 0.497 1952 0.00 15+ Years

C- Manway 36" 0.500 0.499 0.498 0.500 1.000 N/A 0.498 1952 0.00 15+ Years D - 16" Suction 16" 0.375 0.375 0.370 0.375 0.750 N/A 0.370 1952 0.00 15+ Years E - Low Suction 3" 0.250 0.245 0.248 0.250 1.000 N/A 0.245 1952 0.00 15+ Years

F - MW 36" 0.500 0.500 0.495 0.491 1.000 N/A 0.491 1952 0.00 15+ Years

UT: 801-785-1111/AZ: 480-369-6511

API 653 External Visual Inspection Checklist and Report

Item Done Comments

1.1 Foundation

Measure foundation levelness and bottom elevations (see Annex B for extent of measurements).

X See Report

a) Inspect for broken concrete, spalling, and cracks, particularly under backup bars used in welding butt-welded annular rings under the shell.

X OK

b) Inspect drain openings in ring, back of waterdraw basins and top surface of ring for indications of bottom leakage.

X OK

c) Inspect for cavities under foundation and vegetation against bottom of tank.

X OK

d) Check that runoff rainwater from the shell drains away from tank.

X OK

e) Check for settlement around perimeter of tank. X OK

1.1.2 Asphalt A

a) Check for settling of tank into asphalt base which would direct runoff rain water under the tank instead of away from it.

N/A CONCRETE FOUNDATION

b) Look for areas where leaching of oil has left rock filler exposed, which indicates hydrocarbon leakage.

N/A CONCRETE FOUNDATION

1.1.3 Oiled Dirt or Sand

Check for settlement into the base which would direct runoff rain water under the tank rather than away from it.

N/A CONCRETE FOUNDATION

1.1.4 Rock

Presence of crushed rock under the steel bottom usually results in severe underside corrosion. Make a note to do additional bottom plate examination (ultrasonic, hammer testing, or turning of coupons) when the tank is out of service.

N/A CONCRETE FOUNDATION

1.1.5 Site Drainage

a) Check site for drainage away from the tank and associated piping and manifolds.

X OK

b) Check operating condition of the dike drains. X NOT PERFORMED

1.1.6 Housekeeping

Inspect the area for buildup of trash, vegetation, and other inflammables buildup.

1.1.7 Cathodic Protection

Review cathodic protection potential readings. Readings not available for review.

1.2 Shells

1.2.1 External Visual Inspection

a) Visually inspect for paint failures, pitting, and corrosion.

X OK

b) Clean off the bottom angle area and inspect for corrosion and thinning on plate and weld.

c) Inspect the bottom-to-foundation seal, if any. X OK

1.2.2 Internal (Floating Roof Tank)

Visually inspect for grooving, corrosion, pitting, and coating failures.

X OK

1.2.3 Riveted Shell Inspection

a) Inspect external surface for rivet and seam leaks. N/A NOT RIVETED

b) Locate leaks by sketch or photo (location will be lost when shell is abrasive cleaned for painting).

N/A NOT RIVETED

c) Inspect rivets for corrosion loss and wear. N/A NOT RIVETED

d) Inspect vertical seams to see if they have been full fillet lap-welded to increase joint efficiency.

N/A NOT RIVETED

e) If no record exists of vertical riveted seams, dimension and sketch (or photograph) the rivet pattern: number of rows, rivet size, pitch length, and note whether the joint is butt-riveted or lap-riveted.

N/A NOT RIVETED

1.2.4 Wind Girder (Floating Roof Tanks)

a) Inspect wind girder and handrail for corrosion damage (paint failure, pitting, corrosion product buildup), especially where it occurs at tack-welded junction, and for broken welds

X OK

b) Check support welds to shell for pitting, especially on shell plates.

X OK

c) Note whether supports have reinforcing pads welded to shell.

1.3 Shell Appurtenances X OK

1.3.1 Manways and Nozzles

a) Inspect for cracks or signs of leakage on weld joint at nozzles, manways, and repads.

X OK

b) Inspect for shell plate dimpling around nozzles, caused by excessive pipe deflection.

X OK

c) Inspect for flange leaks and leaks around bolting. X OK

d) Inspect sealing of insulation around manways and nozzles.

N/A NOT INSULATED

e) Check for inadequate manway flange and cover thickness on mixer manways.

N/A NOT A MIXER

1.3.2 Tank Piping Manifolds

a) Inspect manifold piping, flanges, and valves for leaks.

X OK

b) Inspect firefighting system components. N/A

c) Check for anchored piping which would be hazardous to the tank shell or bottom…

X OK

d) Check for adequate thermal pressure relief of piping to the tank.

X OK

e) Check operation of regulators for tanks with purge gas systems.

N/A

f) Check sample connections for leaks and for proper valve operation.

X OK

g) Check for damage and test the accuracy of temperature indicators.

X OK

h) Check welds on shell-mounted davit clips above valves 6 in. and larger.

X OK

1.3.3 Autogauge System

a) Inspect autogauge tape guide and lower sheave housing (floating swings) for leaks.

X OK

b) Inspect autogauge head for damage. X OK

c) Bump the checker on autogauge head for proper movement of tape.

X OK

d) Identify size and construction material of autogauge tape guide (floating roof tanks).

X OK

e) Ask operator if tape tends to hang up during tank roof movement (floating roof tanks).

NOT IN SERVICE

f) Compare actual product level to the reading on the autogauge (maximum variation is 2 in.).

NOT IN SERVICE

g) On floating roof tanks, when the roof is in the lowest position, check that no more than two ft. of tape are exposed at the end of the tape guide.

N/A NOT IN SERVICE

h) Inspect condition of board and legibility of board-type autogauges.

N/A N/A

i) Test freedom of movement of marker and float. N/A N/A

1.3.4 Shell-mounted Sample Station

a) Inspect sample lines for function of valves and plugging of lines, including drain or return-to-tank line.

N/A NOT PERFORMED

b) Check circulation pump for leaks and operating problems.

N/A NOT PERFORMED

c) Test bracing and supports for sample lines and equipment.

1.3.5 Heater (Shell Manway Mounted)

Inspect condensate drain for presence of oil indicating leakage.

N/A N/A

1.3.6 Mixer

a) Inspect for proper mounting flange and support. N/A N/A

b) Inspect for leakage. N/A N/A

c) Inspect condition of power lines and connections to mixer.

N/A N/A

1.3.7 Swing Lines: Winch Operation

a) Nonfloating. Raise, then lower the swing line with the winch, and check for cable tightness to confirm swing line lowered properly.

N/A N/A

b) Floating. With tank half full or more, lower the swing line, then let out cable and check if swing has pulled cable tight, indicating that the winch is operating properly.

N/A N/A

c) Indicator. Check that the indicator moves in the proper direction: Floating swing line indicators show a lower level as cable is wound up on the winch. Non-floating swing line indicators show the opposite.

N/A N/A

1.3.8 Swing Lines: External Guide System

Check for leaks at threaded and flanged joints. N/A N/A

1.3.9 Swing Lines: Identify Ballast Varying Need

Check for significant difference in stock specific gravity.

N/A N/A

1.3.10 Swing Lines: Cable Material and

Condition

a) For nonstainless steel cable, check for corrosion over entire length.

b) All cable: check for wear or fraying. N/A N/A

1.3.11 Swing Lines: Product Sample

Comparison

Check for water or gravity differences that would indicate a leaking swing joint.

N/A N

1.3.12 Swing Lines: Target

Target should indicate direction of swing opening (up or down) and height above bottom where suction will be lost with swing on bottom support.

N/A N/A

1.4 Roofs SEE REPORT

1.4.1 Deck Plate Internal Corrosion

For safety, before accessing the roof, check with ultrasonic instrument or lightly use a ball peen hammer to test the deck plate near the edge of the roof for thinning. (Corrosion normally attacks the deck plate at the edge of a fixed roof and at the rafters in the center of the roof first.)

X OK

1.4.2 Deck Plate External Corrosion

Visually inspect for paint failure, holes, pitting, and corrosion product on the roof deck.

N/A N/A

1.4.3 Roof Deck Drainage

Look for indication of standing water. (Significant sagging of fixed roof deck indicates potential rafter failure. Large standing water areas on a floating roof indicate inadequate drainage design or, if to one side, a nonlevel roof with possible leaking pontoons.)

X OK

1.4.4 Level of Floating Roof

At several locations, measure distance from roof rim to a horizontal weld seam above the roof. A variance in the readings indicates a nonlevel roof with possible shell out-of-round, out-of-plumb, leaking pontoons, or hang-up. On small diameter tanks, an unlevel condition can indicate unequal loading at that level.

NOT IN SERVICE

1.4.5 Gas Test Internal Floating Roof

Test for explosive gas on top of the internal floating roof. Readings could indicate a leaking roof, leaking seal system, or inadequate ventilation of the area above the internal floating roof.

NOT IN SERVICE

1.4.6 Roof Insulation

a) Visually inspect for cracks or leaks in the insulation weather coat where runoff rain water could penetrate the insulation.

N/A NOT INSULATED

b) Inspect for wet insulation under the weather coat. N/A N/A

c) Remove small test sections of insulation and check roof plate for corrosion and holes near the edge of the insulated area.

N/A N/A

1.4.7 Floating Roof Seal Systems

a) Inspect condition of seal, measure & record max rim spaces & seal to-shell gaps….

NOTE Inspection of seal and measurement of rim spaces and seal-to-shell gaps at more than one level may be necessary to fully determine if any problems exist at other levels of tank operation).

X OK

b) Measure and record annular space at 30-ft spacing (minimum of four quadrants) around roof and record. Measurements should be taken in directly opposite pairs.

N/A N/A

1) _______ _______ Opposite pair 1.

2) _______ _______ Opposite pair 2.

N/A N/A

c) Check if seal fabric on primary shoe seals is pulling shoes away from shell (fabric not wide enough).

X OK

d) Inspect fabric for deterioration, holes, tears, and cracks.

X OK

e) Inspect visible metallic parts for corrosion and wear.

X OK

f) Inspect for openings in seals that would permit vapor emissions.

X OK

g) Inspect for protruding bolt or rivet heads against the shell.

X OK

h) Pull both primary and secondary seal systems back all around the shell to check their ops.

X OK

i) Inspect secondary seals for signs of buckling or indications that their angle with the shell is too shallow.

X OK

j) Inspect wedge-type wiper seals for flexibility, resilience, cracks, and tears.

X OK

1.5 Roof Appurtenances

1.5.1 Sample Hatch

a) Inspect condition and functioning of sample hatch cover.

X OK

b) On tanks governed by Air Quality Monitoring District rules, check for the condition of seal inside hatch cover.

X OK

c) Check for corrosion and plugging on thief and gauge hatch cover.

X OK

d) Where sample hatch is used to reel gauge stock level, check for marker and tab stating hold-off distance.

X OK

e) Check for reinforcing pad where sample hatch pipe penetrates the roof deck.

X OK

f) On floating roof sample hatch and recoil systems, inspect operation of recoil reel and condition of rope.

g) Test operation of system. N/A N/A

h) On ultra clean stocks such as JP4, check for presence and condition of protective coating or liner inside sample hatch (preventing rust from pipe getting into sample).

X OK

1.5.2 Gauge Well

a) Inspect visible portion of the gauge well for thinning, size of slots, and cover condition.

X OK

b) Check for a hold-off distance marker and tab with hold-off distance (legible).

X OK

c) On floating roofs, inspect condition of roof guide for gauge well, particularly the condition of the rollers for grooving.

X OK

d) If accessible, check the distance from the gauge well pipe to the tank shell at different levels.

X OK

e) If tank has a gauge well…